Angle-Sensitive Pixel Device Using Talbot Effect for 3D Light Field Capture
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Solution Overview
Problem
Conventional imaging technologies fail to capture the incident angle and polarization properties of light rays, limiting their ability to provide a complete description of the light field, which is essential for three-dimensional reconstruction and other applications, and require additional optical components that increase complexity and cost.
Innovation Solution
The development of lens-less, angle-sensitive pixel (ASP) devices that utilize periodic light diffracting structures and Talbot effect to measure the intensity and direction of light, allowing for the creation of a pseudo-3-D CMOS imaging device that captures light field information without the need for lenses or additional optical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional imaging uses a large array of light sensors to create an intensity map, then the intensity measurement is improved, but the incident angle and polarization information is lost
Solution Approach 1:
Each pixel is segmented into multiple sub-pixels with different optical axis orientations. This allows each pixel to simultaneously measure intensity and angular information by comparing responses from sub-pixels with different orientation sensitivities, thereby recovering incident angle data without sacrificing intensity measurement precision
Solution Approach 2:
The invention adds angular dimension measurement to the traditional two-dimensional intensity mapping. By incorporating micro-lens arrays with different optical axis orientations, the system transforms pure intensity measurement into a multi-dimensional measurement that includes both intensity and incident angle information
2Adaptability or versatility
If lenses and additional optical components are added to capture light field information, then the light field measurement capability is improved, but the device complexity and cost increase
Solution Approach 1:
The invention merges the functions of multiple optical components (lenses, angle sensors, polarization detectors) into a single integrated pixel structure. The micro-lens array is directly coupled with the sensor array, eliminating the need for separate optical components and reducing overall system complexity while maintaining light field measurement capability
Solution Approach 2:
Each pixel unit serves multiple functions: it measures intensity, determines incident angle, and can detect polarization information. This multi-functionality is achieved through the micro-lens array configuration where each lens or group of lenses has specific orientation characteristics, allowing a single pixel structure to replace what would traditionally require multiple separate devices
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the extraction of three-dimensional structure information from light sources, allowing for accurate localization of light sources in three-dimensional space and reconstruction of three-dimensional surfaces, while reducing the size and cost of imaging instruments by eliminating the need for complex optical systems.
Implementation Method 1
The disclosed apparatus and methods utilize the Talbot effect of periodic light diffracting structures to characterize incident light by its magnitude and direction.
Implementation Method 2
pixel devices disclosed herein are sensitive to both the intensity and the incident angle of incident light from an object scene. The disclosed apparatus and methods utilize the Talbot effect of periodic light diffracting structures
Data Source
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AI summary
An angle-sensitive pixel (ASP) device that uses the Talbot effect to detect the local intensity and incident angle of light includes two local diffraction gratings stacked above a photodiode. When illuminated by a plane wave, the upper grating generates a self-image at a selected Talbot depth. The second grating, placed at this depth, blocks or passes light depending upon incident angle. Several such structures, tuned to different incident angles, are sufficient to extract local incident angle and intensity. Arrays of such structures are sufficient to localize light sources in three dimensions without any additional optics.